In 2002, the mobile phone service of the 3G system called the third generation in Japan started. Initially, small-size packets were transmitted and received for transmission of voice calls and mails. However, with the introduction of high speed downlink packet access (HSDPA), it became possible to transmit and receive larger-size packets for downloading of music files or streaming of video. With such an increase of packet capacities, the service of long term evolution (LTE) in which orthogonal frequency division multiple access (OFDMA) is used for downlink also started for the expansion on the side of the wireless network. In addition, the start of the 4G service is planned for around 2015. Accordingly, up to 1 Gbps (bit per second) is realized in a semi-fixed state and also up to 100 Mbps is realized even in a moving environment.
With an increase in traffic as described above, it is expected to avoid concentration of traffic by arranging small base stations that are inexpensive and whose installation is easy. With the arrangement of such small base stations, on the other hand, there are concerns about increased power consumption. Thus, various technologies have been proposed to curb power consumption of small base stations.
For example, PTL 1 and PTL 2 disclose a technology that causes a femtocell base station to stop reception of a radio wave when it is determined that no radio communication terminal is present near the femtocell and causes the femtocell base station to start reception of a radio wave when it is determined that a radio communication terminal is present near the femtocell.